The need for videos having high resolution and high quality has recently been increasing in various fields. As the resolution and quality of a picture is improved, however, the amount of data in the video is also likewise increased. Accordingly, if video data is transmitted using a medium such as an existing wired/wireless broadband line, or video data is stored using an existing storage medium, the costs of transmitting and storing data are also increased. In order to effectively transmit, store, and play information within a picture having high resolution and high quality, video compression technology utilizing high efficiency can be used.
In order to improve video compression efficiency, inter-prediction and intra-prediction can be used. In inter-prediction, pixel values within a current picture are predicted from a picture that is temporally anterior and/or posterior to the current picture. In intra-prediction, pixel values within a current picture are predicted using pixel information within the current picture.
In addition to the inter-prediction and intra-prediction methods, weight prediction technology for preventing picture quality from being deteriorated due to a change of lighting, entropy encoding technology for allocating a short sign to a symbol having high frequency of appearance and allocating a long sign to a symbol having low frequency of appearance, etc. are being used for the efficient processing of information within a picture.